Headlight / Dash Light Help Needed

[ggerline]

Hi all, new member and first post. I have a 79' C10. Just upgraded the headlights recently to a LED Headlights (Round Headlights). After doing this, when I try to turn on my dash lights using the dimmer switch, the headlights will not change from High to Low or vice versa. If I turn the dash lights all the way off using the dimmer switch, I can cycle through the headlight modes, but no dash lights. I purchased a relay after this hoping it would fix the issue, allowing the headlights to run directly off the battery and not the headlight switch. Just trying to be able to turn up the dash lights on the dimmer switch so I can see my gauges and also cycle headlights from low to high / high to low like normal. Any help/ideas would be very much appreciated.

 

[theblindchicken]

I'm assuming they worked perfectly while using sealed beams / incandescent headlights?

I would check the output voltage coming through the headlight switch while changing the adjusting the dash lights.


It sounds like the switch is cutting down the voltage too much for the relay and the LED headlight to fire (LEDs are very sensitive to voltage changes). If the voltage drops a bit, an incandescent bulb will dim, but an LED can just turn off.